So, the spiffy new wi-fi thermostats want power on the C wire from thermostat, but the old thermostat doesn't have a C wire at it. What's the easiest way to add the C wire/24 volt to the thermostat ...

I am installing a new honeywell WiFi thermostat but the old battery operated thermostat had batteries and no "C" wire. I look at both the thermostat and the air handler and found an extra un-used blue ...

I have spent hours searching the web for information on this 20+ year old zone control panel, which supports 3 zones of Heat and A/C.
The thermostat I'm replacing (on Zone 3) connects to T4/T5/T6 as ...

I have a Laars gas boiler that has 3 heating zones. I want to replace the old mercury honeywell tstat on the 1st floor (heat only) with a newer honeywell RTH9580 wifi model. I've taken pictures of my ...

I'm trying to install a wireless thermostat but i ran into issue putting in an external thermostat. I have a 2 Stage Cool / 1 Stage heat system.
I have the Red 24V from Air Handler connected to R. I ...

I Purchased the Honeywell WiFi Prog Thermostat to replace my Round Digital Honeywell Thermostat.
I have separate Heating and Cooling (Heating is a Weil McLain Boiler for Hot water baseboard and Hot ...